Pulley for a conveyor belt



Jan. 9, 1962 M. F. CNUDDE mummy FOR A CONVEYOR BELT Filed April 26, 19 60 O Q Q 0 O O O Q 6 O O L O 9 2 O O O 0 United States Patent PULLEY FOR A CONVEYOR BELT Maurice F. Cnudde, 51B Chaussee de Charleroi, Brussels 6, Belgium Filed Apr. 26, 1960, Ser. No. 24,697 Claims priority, application Belgium May 13, 1959 a 4 Claims. (Cl. 263-8) The invention relates to a pulley for an endless conveyor belt and particularly to a pulley for a belt travelling through heat treatment furnaces such as an annealing furnace for glass articles.

Since the articles to be treated in a furnace of this kind generally enter the furnace in the hot state and issue from the furnace in the cooled state, the belt is generally driven at the furnace exit by a driving pulley about which is looped the belt which then returns towards the entrance, becom-ing heated during its return travel. At the entrance, it passes about a reversal pulley and before receiving the appropriate load, its temperature has to be brought to the temperature of the load by an additional heating arrangement. This heating of the belt involves the heating of the reversal pulley. According to its diameter, the pulley is generally solid or is constituted by a tube provided at its ends with journals supported by bearings. The pulley absorbs an appreciable quantity of heat and its high temperature is communicated to the journals and the bearings, which, therefore, are subjected to rapid wear.

A further disadvantage is that the choice of metals which can be used for tubular pulleys is very limited. It is necessary to restrict the choice to mild steel tubes which do not resist very well the high temperature to 3,016,235 Patented Jan. 9, 1962 by way of example in the accompanying drawings in which:

FIGURE 1 is a view, partly in elevation and partly in axial section, of a pulley in accordance with the invention;

FIGURE 2.is a sectional view taken on the line II-Il of FIGURE 1; and

FIGURE 3 shows a jet-type heating pipe.

The pulley comprises bars 1 made'of a refractory steel which are engaged in radial notches in end discs 2 to constitute a squirrel cage pulley. Journals 3 are fixed at each side of the pulley to the two end discs and are supported by bearings (not shown in the drawings). The journals are hollow and through one of them there extends an axial heating jet pipe 4 supplied with gas at one end 5 see FIGURE 3 and provided with orifices 6 located around that portion of the pipe which is arranged to be situated Within the squirrel cage pulley between the journals. The flames reach the conveyor belt directly through the bars and the journals are kept away from the heat.

The invention is not, of course, limited to the form of embodiment which has been described and illustrated by way of example, and modifications could be made thereto without departing from the scope'of the said invention.

I claim:

1. A hollow reversal pulley for an endless conveyor which they are exposed, and are rapidly made unusable by oxidation and deformation.

The reversal pulley according to the present invention overcomes the many disadvantages of the pulleys which are at present in use in annealing furnaces.

According to the invention the pulley is constituted by a squirrel cage through whose bars the conveyor belt can be heated to the requisite temperature, whilst avoiding subjecting the bearings of the pulley journals to a harmful amount of heat. The mass of the squirrel cage and, therefore, the heat lost, are less than in the case of solid or tubular pulleys. Furthermore, refractory steel bars of suitable dimensions are generally available from steel producers.

The pulley constituted by a squirrel cage advantageously comprises discs connected together peripherally by the bars which are lodged in radial notches of the discs, journals being fixed at each side of the cage to the, two end discs. These journals are preferably hollow and make it possible to introduce axially of the pulley through one of them a heating means constituted by a jet pipe whose flames are directed towards the belt. surfaces at which the bars and discs contact one another are small mama and the end discs are not exposed to the flames, the journals and bearings cannot become heated in a manner detrimental to their satisfactory operation.

One form of embodiment of the invention is illustrated Since the discs in spaced relation, a shell connected to said discs, said shell including a plurality of flat bars spaced on said discs, a hollow journal coaxially fixed on each of said side discs and heating means extending between said journals for heating said pulley and conveyor belt.

2. A hollow reversal pulley for an endless conveyor belt,-said pulley comprising: first and second. side circular discs in spaced relation, a shell connected to said discs,

said shell including a plurality of flat bars spaced on said discs, hollow journal members, each of said discs being coaxially supported on one of said journal members, and heating means extending axially in said journals for heating said pulley and conveyor belt, said heating means being axially movable with respect to said journals.

3. A pulley as claimed in claim 2 wherein said heating means includes a circular pipe provided with a plurality of apertures, said pipe being adapted for connection with a source of heat.

4. A pulley as claimed in claim 2 wherein said flat bars are equally spaced along the periphery of the circular side discs and are radially directed therewith, said flat bars extendingin part radially beyond theperiphery of Hageline Apr. 9, 1957 

